This invention relates to mechanically operated disc brakes, and more particularly to improvements in such disc brakes wherein the position of a friction pad can easily be adjusted when the friction pad has worn.
Conventional mechanically operated disc brakes receive the input force in a rotational direction which is applied through a cable or the like associated with a brake pedal or a brake lever and convert the rotational input force into a linear output force thereby effecting the braking action. For converting the force in a rotational direction into the force of the linear direction there are usually provided a nut member for receiving the rotational input force, and cooperating ramp surfaces, preferably having a ball therebetween, formed respectively on the nut member and a ramp member, whereby the rotational movement of the nut member is converted into the linear movement. Further, an adjusting rod threadingly engages the nut member and abuts with one of friction pads for transmitting a thrust force from the nut member to the friction pad thereby applying the same against one surface of a disc. When the friction pad has worn, the adjusting rod is rotated relative to the nut member to compensate for the wear of the friction pad. For preventing incidental rotation of the rod member, there has usually been provided a rotation control member. However, the rotation control members of prior art disc brakes have a complex construction and are troublesome to assemble and maintain.